The Radiation Therapy Oncology Group was founded in 1971 for the purpose of constituting a group of clinical radiation therapy investigation centers for the purpose of conducting trials and other studies to improve the management of patients with cancer. Funding was via the Clinical Investigations Branch of the National Cancer Institute, and the University of Washington was one of the 19 founding members. As of January 1978, there were approximately 30 full-member institutions and 11 provisional member intitutions in the RTOG. Through the efforts of this group, the RTOG statistical center at Thomas Jefferson University Hospital has evaluable treatment and follow-up data on over 6000 patients who have been entered on randomized trials. Through the collaboration of these radiotherapy centers, it is possible to provide an adequate number of patiens to answer significant questions in the treatment of cancer not possible on the basis of the number of patients seen in any one institution. The University of Washington has participated effectively in accruing patients for these randomized studies since 1971. We are currently participating in 10 ongoing protocols and 4 registries and have interest in participating in at least 4 other upcoming protocols. The purpose of this grant is to insure our continued effective support of these important clinical cancer trials.